Cowhides are tanned to make Leather or Hard Leather. These are then used in the Crafting skill to make various items, mostly useful to rangers. These include Leather gloves. Leather chaps, Coifs, Cowls, Vambraces, and Hardleather bodies.
They can be attached to any vambraces except snakeskin and third age to make spiked vambraces. These add a +2 strength bonus to the vambraces.
You can buy them from Thessalia in Varrock.
get 10 defense, then buy your hard leather, and then you can wear it.
Just buy in Grand Exchange
Well, depends what your training with, if your training range, but arrows. If your training crafting, buy leather/moulds/gold ect.
buy or kill cows for there hides get there hides tanned get a needle and thread and make leather cowls
Craft Kebbit Claws onto them, check the required Crafting level you need, if you don't have it then you can always use the Request System.
You get crafting experience.
Leather Gloves
the grand exchange on runescape
the same way you make leather